Concussion, sometimes called a mild traumatic brain injury (mTBI), is an acquired brain injury resulting in alterations to brain function underpinned by a sequence of neuropathological and neurometabolic events that can result in excitotoxicity, oxidative stress, oedema, neuroinflammation and cell death. To date, pharmaceutical therapies have had limited success in treating TBI, presenting considerable interest in nutritional therapies in the form of dietary supplementation to alleviate the deleterious pathological sequelae following neurotrauma. Many nutritional supplements have low toxicity, few drug interactions, and are already approved for human use making them attractive potential therapies following a concussion. In the setting of brain injury models, a considerable body of preclinical evidence has accumulated supporting the use of nutritional supplements including essential fatty acids, vitamins, minerals, amino acids, polyphenols, bioflavonoids and other bioactive compounds to facilitate aspects of functional recovery. Here, we review studies presenting diet supplements as therapeutic strategies as potential treatments for mTBI or to augment neurological resistance against mTBI in experimental models, as well as emerging therapeutic targets including the gut microbiome, and psychedelic and non-psychedelic compounds derived from fungi.